How many things, both just and unjust, are sanctioned by custom!

Custom sanctifies the just and the unjust in exactly the same tone of voice. A practice that has been running long enough stops being examined at all: nobody defends it, because nobody notices there is anything to defend. Length of service tells you how long something has lasted and nothing whatever about whether it should.

Pick one arrangement in your workplace or your family that has always simply been the way it is done. Ask who benefits from it, who bears it, and what would happen if it stopped. Most of the time the answer is harmless and occasionally it is not, and you will not know which until you look.